Arriving after the arranged time to a meeting or event that does not require strict punctuality, especially so as to give the appearance of nonchalance or having been preoccupied by other social engagements. A: "John's party is starting in 20 minutes, so we'd better get moving soon!" B: "No one will even be there by then. Haven't you ever heard of being fashionably late?" Mary doesn't like to appear overeager when she goes to parties, so she always makes a point of being fashionably late.